A tale of a shaggy soldier
If you came to the brilliant talk this year by Leif Bersweden you may remember that Leif once nearly got arrested for his interest in botany! During a New Year plant count Leif was on his knees attempting to identify a small plant in the daisy family, Galinsoga quadriradiata (Shaggy soldier which is very similar to “Gallant soldier” (Galinsoga parviflora). As he was outside the Ministry of Justice at the time, his strange behaviour had been caught on all the security cameras, and an unimpressed security guard insisted he moved on!
Since then we have been looking out for this little daisy plant! And recently we found it, a first recording for the plant in Seaford! Where was it? In one of our beautiful nature reserves or managed parks? No just outside the door of Morrisons! Keep looking down, you never know what you will see!
Brian shares his findings and a lesson on daisy anatomy!
Galinsoga is a daisy, the Latin name of which has, in English, been corrupted to “Gallant Soldier”. Two species occur in England. Galinsoga quadriradiata is the more common one. Since it is a very hairy plant it is called “Shaggy Soldier” whilst the other, less common species is plain “Gallant Soldier”, Galinsoga parviflora (parviflora meaning “small flowered”).
(A) Here is a single flowerhead supported on blob of bluetack and the scale is in millimeters. They are small but the re-semblance to a common or garden daisy is obvious The white petals around the edge are the ray flowers or ligules while the yellow ones in the centre are the disc flowers. The ray flowers’ single petals each have three or two lobes so the appearance of 12 petals is in fact formed by only 5 ray flowers. There were 15 disc flowers in this specimen.
(B) As can be seen here Shaggy Soldier is very hairy (“pubescent”) and in practice this is the most obvious difference between the two species. Gallant Soldier does have hairs but they are much less profuse. Usually the difference is very obvious but since it is a matter of degree of hairiness there can be some overlap. Then other, less obvious features have to checked.
(C) In this close up it can be seen that many of the hairs have tiny swellings on their tips. These are glands. In plants, hairs* are actually made up specially shaped living cells so they can secrete fluids. These may attract pollinating insects or they may repel plant eaters. The presence of these glandular hairs is more typical of Shaggy Soldier. This is when it is useful to have a magnifying lens.
*technically these structures are called “trichomes” rather than hairs and they can have alternative functions in other species, instead of producing secretions e.g absorbing water.
(D) This flower head (also pictured at the top of this page) has been stuck onto a piece of bluetack and pulled apart a bit. In the top picture, the outer layer of green “bracts”* has been partly removed exposing the yellow disc flowers. In the main picture above, can be seen some seeds which change from white to black when mature. The yellow tube flowers sit on top of them, as do the white ray florets. These seeds look much the same in both species of Galinsoga but there is a difference.
*for the difference between bracts and leaves see note 1 at the end of this piece.
(E) On the left (E1) a mature seed from one of the yellow disc flowers. On the right (E2), one of the white ray flowers wth an immature seed still attached below the flower parts. The three lobed white petal curls into a tube out of which protrudes the yellow style with its bifid stigma. Pollen that gets onto the stigma burrows its way down the style into the seed to fertilise it. Until that happens the white structure below is technically a “carpel” containing an unfertilized egg or “ovule”.
(F) On the top of the carpel in E2 is a hairy structure that hides the attachment of the style and the tubular portion of the ray flower. This is the seed’s “pappus”. which meant bristles or hairs in ancient Greek. The pappus is a characteristic feature of daisies and varies in shape from the hairs of the dandelion’s clock to a simple non-hairy collar of tissue surrounding the top of a seed.
(G) In the Shaggy Soldier seed (E1), the pappus looks like a tuft of hairs but in fact it is a ring of papery scales each covered in hairs or bristles which is best seen where a scale appears in profile at the sides of the tuft. Here, the top of the seed is shown against a dark background at each side-on view of a pappus scale shows as solid (red arrows). In between, the silvery hairs on the surface of the scale hide its shape. In fact, as outlined, scales are rather pointed or triangular shaped with a bristle at the apex. This is different from Gallant Soldier in which the hairs form only a fringe and the scale has a blunt apex not pointed.
Technically these are actually fruits with a single seed inside.
It has to be said that distinguishing the two species by these secondary features ( the glandular hairs and the shape of the pappus scales) are not easy to do in the field even with a hand lens!
These images were photographed with a dissecting microscope. In practice, if your specimen of Galinsoga is very hairy, it is going to be Shaggy Soldier.
In fact both species are scarce in East Sussex with Shaggy Soldier being the more frequent. However they have both been recorded in Seaford Bay area but over at Newhaven. They may just have been overlooked in Seaford. Thus our finding in the pavement cracks of Dane Road is worth recording. It is also worth distinguishing which species we have found, hence all the points noted above. There is one further way of being sure but again a hand lens is necessary.
If you use Rose’s Wild Flower Key or Collins Flower Guide, they both emphasise the difference between the shape of the receptacle scales in the two species….but what are those?
Plants like Galinsoga are in the daisy family and they have composite flower heads.
In this very rough sketch of a section through the composite daisy flowerhead, the
receptacular scales (when present…..many species do not have them) are shown in red. They vary in size and shape between species. Both of our Galinsoga species have them. Returning to the image of the opened flower on its blob of bluetack, the scales can be seen in front of the yellow disc flowers. They are quite papery, flat, flimsy structures and not so easy to see without a lens in flowers the size of Galinsoga. Here they are simple shape without any lobes. You might be able to see a fringed appearance at their edges. This unlobed shape is typical of Shaggy Soldier while in Gallant Soldier, in which they have three lobed shape (see the pictures in Rose “Wild Flower Key”)
Note 1 Bracts and Leaves
Bracts are leaf-like structures that are immediately below a flower or, as in the daisy family, below a flower head. Leaves arise from the main plant stem and there is usually a bud (though it may never open) in the angle between the main stem and the leaf stalk.
On daisies there is a ruff of bracts, often in several overlapping rows that form an envelope or involucre around the florets on the flower head. (see sketch) The arrangement and detailed structure of these “involucre bracts” can be helpful in identifying flower heads that are otherwise very similar (eg the dandelion look-alikes such as Hawksbit and Hawk’s-Beard) and they are technically called “phyllaries.
Final notes
Neither of the Galinsoga species are native to the this country. They come from a large group of plants in South/Central America. In the 18th century Spain, the colonial power sent out several major botanical expeditions and the two botanists on the first of these were Hipolito Ruiz Lopez and Jose Pavon Jimenez who went to Peru and Chile for several years.
Don de Galinsoga was the director of the Botanical Garden back in Madrid and they named this genus of plants after him. They did not distinguish between our two species calling them both Galinsoga quadriradiata. The second part of this name obviously refers to some floral feature that shows 4-angled radiation but if you can see what it is, please let us know. Gallant Soldier was distinguished from the specimens back in Madrid Botanical Garden by the next Director Antonio Cavanilles (who first described many other genera such as “Dahlia”).
At least the Latin for Gallant Soldier Galinsoga parviflora (Galinsoga with small flowers) makes sense. The flowers are certainly small. Specimens of this species arrived at Kew at the end of the 18th century but were not found in the wild here ‘til mid 19th Century. It is most common in the South East but scarce in East Sussex. G.quadriradiata arrived later and is now considered to be more the more common. However like parviflora, it is scarce in East Sussex so both are worth looking out for on waste ground. G.quadriradiata is more often seen on roadsides and pavement cracks.
Brian Livingstone
Notes of more observations would be welcome please
